Think Big

What is the greatest technological
innovation of the past 1,000 years? A hint: It's not just the thought that
counts.

By

Bob Davis

Updated Jan. 11, 1999 12:01 a.m. ET

In the history of technology, Thomas Edison's laboratory in Menlo Park, N.J., established in 1876, is justly celebrated. How much darker, in many ways, the millennium would have been if Mr. Edison and his mechanics and engineers hadn't invented a practical system for lighting cities. (The Wall Street area was the first place illuminated -- technology invariably chases money.)

But compare Mr. Edison's efforts with those of a little-known predecessor, Prince Henry the Navigator of Portugal. Around 1420, the Portuguese prince...